When I SSH to a SunOS Box from Cygwin on Putty (puttycyg) on Windows and attempt to use vi, I get the following:
I don't know what kind of terminal you are on - all I have is 'cygwin'
This fix is easy enough, and I got the clue from this forum post: Solaris 10, PuTTY, and vi. Edit
~/.bashrc and add the following:
TERM=xterm; export TERM